Early in Saturday’s second practice of the day, receiver Charles Nelson was a standout in a live special teams drill, twice blasting his way past blockers and tackling return men. Later, in one of the final reps of the day, linebacker Jimmie Swain burst through the line in a team drill and the play was whistled dead as a sack.

Nelson and Swain are a couple of the true freshmen who consistently stood out over the course of the first week of Oregon’s preseason camp, which ended Saturday. Also, UO coach Mark Helfrich said, they’re guys who consistently have their heads in their playbooks, or are watching video on their iPads, when Helfrich sees them around the Hatfield-Dowlin Complex.

“There’s probably a correlation,” Helfrich said today after practice.

Nelson’s two plays were highlights of one of camp’s most physical periods so far, a drill in which a kick coverage player has to defeat a block and then bring down a ballcarrier. Devon Allen also won a couple of reps as a coverage guy, Johnny Ragin III was a standout in sustaining blocks for the runners, and Johnathan Loyd was able to avoid tackles a couple different times while running with the ball.

Nelson has been in the mix to return kicks, but in this instance he was used in coverage. While listed at but 5-foot-8 and 167 pounds, he didn’t back down from the challenge, drawing boisterous praise from UO special teams coach Tom Osborne.

“Coach Osborne just wants his special teams to go fast,” Nelson said. “I just tried to do everything he’s taught us in meetings and execute it well, and I guess it worked.”

Along with putting in extra work outside of practice, as Helfrich noticed, Nelson stayed late Saturday – following the second practice of the day – and was one of the last guys off the field after catching extra passes from Marcus Mariota. Nelson has worked in the rotation of receivers with the two-deep this week, and he got deep for a reception from Jeff Lockie in 7-on-7 today.

“I feel like it went well,” Nelson said of the first week of camp. “Pretty successful first week for us, and (yet) I feel like we’ve got a lot more to do to get better, and we’ll handle that.”

Highlights: The Ducks did a bunch of stuff down toward the red zone this afternoon, beginning with the tempo drill to kick off practice. Mariota connected with Allen on a touchdown, and Byron Marshall ran for one. Arik Armstead corralled Marshall on another carry, and Chris Seisay tipped a ball into the air that Khalil Oliver nearly picked off. Late in the drill, Thomas Tyner got into the backfield’s monster truck party – begun Friday by Royce Freeman and Kani Benoit – by putting a defender on his back at the goal line.

During later red-zone work, Mariota had a scoring pass to Darren Carrington, and might have had another depending on whether Johnny Mundt could have shrugged off a cornerback’s hit near the goal line, had the drill been live. Troy Hill intercepted a ball in the end zone while filling in with the threes, Seisay and Justin Hollins came up to limit ballcarriers to short gains, and Tyner and Freeman rushed for scores.

Other observations: After that late period in the red zone, Helfrich threw in a surprise field-goal attempt, of 32 yards, which Matt Wogan converted. … Loyd caught a bunch of balls this afternoon, and Seisay stood out to cap a surge over the final couple days of the week. … Sticking with a couple consistent themes this week, Dwayne Stanford won a battle for a deep jump ball, and Tony Washington was effective dropping into coverage and breaking up a pass. …

Andre Yruretagoyena won a couple reps in pass rush, and came about as close to neutralizing DeForest Buckner on a rep as I’ve seen this week. Matt Pierson and Braden Eggert also had successful efforts on offense, while Henry Mondeaux (twice), Buckner and Tui Talia recorded “wins” for the defense in my notebook. Jake Fisher and Armstead engaged in a really even battle, which I wasn’t sure how to score. … Lockie’s completion to Nelson in 7-on-7 came in the middle of a nice sequence in which the UO backup quarterback hit Chance Allen despite tight coverage by Oliver, connected deep with Nelson and then completed a third straight ball, to Loyd.